1. Field of the Invention
This invention relates to a device and method for creating a region of hemostasis along a wall of a blood vessel without interrupting the flow of blood through the blood vessel. The device may be used, for example, for creating a working area along the aorta for performing a cardiac bypass procedure or for isolating an aneurysm.
2. Background Discussion
Coronary artery diseases are often caused by atherosclerosis or narrowing of the small arteries between the aorta and the heart muscles. There are several ways to provide blood flow around occluded segments of arteries or veins, however, the known methods cause a large amount of trauma to the patient. One method is to perform an "open heart surgery," which is cracking open the chest and exposing the heart and treating the vessel directly. However, the large incision and surgically cut sternum take a long time to heal.
Another method is to perform a bypass operation wherein a section of the saphenous vein, or a suitable substitute, is grafted, usually between the ascending aorta just above the heart and one or more of the coronary arteries beyond the points of blockage. The bypass operation is performed with the patient connected to a heart-lung machine and the heart is stopped. Because the heart is stopped, the heart-lung bypass can damage blood cells. Additionally, the patient's internal body temperature is reduced while on a heart-lung bypass to reduce basil metabolism and then the body temperature is increased to normal when the procedure is over. This thermal change to a person's body can cause damage to the intestinal track as well as causing additional stress to the patient.
If the patient is not placed on a heart-lung bypass, the aorta is typically partially clamped along its axis to create an area of blood stasis and a small channel for blood flow. However, clamping the aorta can cause injury to the aorta and can also cause plaque formations to break off into the blood stream and cause vascular accidents such as strokes and emboli.
What is needed therefore is a device and method for performing a cardiac bypass procedure without the need to clamp the aorta or place the patient on a heart-lung bypass machine.